A thermoplastic resin has improved properties such as lower specific gravity than glass or metal and improved formability, impact resistance, and the like. Recently, as various products have become larger, thermoplastic resins have replaced conventional glass and/or metal to reduce the weight of the products and to reduce costs. Thermoplastic resins have been widely used, for example, in the manufacture of products ranging from electric/electronic products to auto parts.
Recently, a low gloss resin has been increasingly required to meet increasing demand for a non-painted resin. For example, there has been an increased demand for a material having low gloss or no gloss characteristics for use as an environmentally-friendly and cost-cutting interior/exterior auto/electric/electronic material and in particular, a low gloss product satisfying customers' demand for a high-quality appearance of an auto interior material.
Since an auto interior material requires excellent weather resistance/light resistance as well as excellent heat resistance and impact strength, a mixed resin of a polycarbonate resin having excellent heat resistance and impact strength and a rubber modified acrylic-based graft copolymer having excellent weather resistance/light resistance and formability is widely used.
The mixed resin can be used as an auto interior material due to its excellent properties and weather resistance. There is still a need, however, for a low gloss resin to realize high-quality appearance without painting. U.S. Pat. No. 4,460,742 discloses a low gloss composition prepared by adding a copolymer cross-linked by an allyl functional group.
Many low gloss resins are prepared by adding rubber particles having a large diameter or a matting agent to the resin or by injection molding the resin composition using a particular corrosion mold selected to decrease gloss.
Sufficient low gloss effects may be obtained using large amounts of the rubber particles having a large diameter or the matting agent. Using large amounts of the rubber particle having a large diameter or the matting agent may, however, deteriorate properties such as impact strength and the like.
In addition, using a corrosion mold can increase costs because different molds are required depending on the degree of gloss. Further, it can be difficult to adjust the gloss as needed.
Further, rubber particles having a large diameter can have limited weather and/or light resistance. Accordingly, a matting agent is mainly added to the resin to decrease gloss. The matting agent, however, can deteriorate properties such as impact strength, heat resistance, and the like when used in the large amounts required to provide sufficient low gloss characteristics.